Various steering systems are available for marine vessels, boats, ships and the like. At a general level these systems usually comprise a helm wheel or steering joystick which controls one or more steering devices located at the stern of the marine vessel.
The type of steering device(s) utilised often depends on how the marine vessel is propelled through the water. The steering device for a propeller driven marine vessel may simply be a rudder, or the propeller itself may be pivotable in the case of an outboard motor or stern drive. For watetjet driven marine vessels, steering deflectors or nozzles which control the direction of one or more waterjets are usually provided as steering devices.
Many steering systems, particularly for larger boats or vessels, include an electronic control system which interfaces between tie steering input device, such as a helm wheel or steering joystick, and the actuator(s) for the steering device(s). These control systems are generally configured so that there is a fixed relationship between the amount that the steering input device is moved and the actual angle or position of the steering device(s).
With such electronic based steering systems, the pilot of a marine vessel directly controls the steering device(s) in order to turn the vessel via operation of the steering input device. However, because in practice there are always external disturbances such as wind, waves, tidal currents and vessel directional instabilities, the angle or position of the steering device(s) does not necessarily reflect how the vessel will actually turn. Often the pilot or helmsperson must constantly adjust the steering input device in order to maintain either a straight course or a particular desired rate of turn.
International patent application publication WO2005/054050 in one embodiment discloses a system for controlling a watercraft which has the objective of preventing overshoot when the watercraft is coming out of a turn. When the helmsperson returns the helm from a “command turn” position to a neutral or ahead position, the system then operates to prevent overshoot in coming out of the turn.
It is an object of the present invention to provide an improved steering system for a marine vessel, or to at least provide an alternative steering system.